Showing papers by "Erminia Calabrese published in 2009"
TL;DR: In this article, the authors investigated the impact of a nonstandard time evolution of the dark matter component on current cosmological bounds from cosmic microwave background (CMB) anisotropies, finding that less than 0.1% variation in the effective dark matter equation of state w{sub dm} can drastically change current CMB bounds on the matter density, the Hubble parameter and the age of the universe.
Abstract: We investigate the impact of a nonstandard time evolution of the dark matter component on current cosmological bounds from cosmic microwave background (CMB) anisotropies. We found that a less than 0.1% variation in the effective dark matter equation of state w{sub dm} can drastically change current CMB bounds on the matter density, the Hubble parameter and the age of the Universe. A flat universe without dark energy could provide an excellent fit to current CMB data, providing that w{sub dm}{approx}-10{sup -2}.
31 citations
Posted Content•
TL;DR: In this article, the authors focus on the pattern of polarization in the Cosmic Microwave Background (CMB), which is uniquely sensitive to primordial gravity waves and propose a method to map CMB polarization over the next decade.
Abstract: Modern cosmology has sharpened questions posed for millennia about the origin of our cosmic habitat. The age-old questions have been transformed into two pressing issues primed for attack in the coming decade: How did the Universe begin? and What physical laws govern the Universe at the highest energies? The clearest window onto these questions is the pattern of polarization in the Cosmic Microwave Background (CMB), which is uniquely sensitive to primordial gravity waves. A detection of the special pattern produced by gravity waves would be not only an unprecedented discovery, but also a direct probe of physics at the earliest observable instants of our Universe. Experiments which map CMB polarization over the coming decade will lead us on our first steps towards answering these age-old questions.
22 citations
TL;DR: In this article, the authors investigate the possible constraints on the integrated lensing potential from future cosmic microwave background angular spectra measurements expected from Planck and EPIC, and find that Planck will constrain the amplitude of the integrated projected potential responsible for lensing at 6% and 1% level, respectively, with very little sensitivity to the shape of the potential.
Abstract: Weak gravitational lensing leaves a characteristic imprint on the cosmic microwave background temperature and polarization angular power spectra. Here, we investigate the possible constraints on the integrated lensing potential from future cosmic microwave background angular spectra measurements expected from Planck and EPIC. We find that Planck and EPIC will constrain the amplitude of the integrated projected potential responsible for lensing at 6% and 1% level, respectively, with very little sensitivity to the shape of the lensing potential. We discuss the implications of such a measurement in constraining dark energy and modified gravity scalar-tensor theories. We then discuss the impact of a wrong assumption on the weak lensing potential amplitude on cosmological parameter inference.
20 citations
05 Mar 2009
TL;DR: The Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT) are outfitted with a new generation of custom mm-wave kilo-pixel arrays as mentioned in this paper.
Abstract: How did the universe evolve? The fine angular scale (l>1000) temperature and polarization anisotropies in the CMB are a Rosetta stone for understanding the evolution of the universe. Through detailed measurements one may address everything from the physics of the birth of the universe to the history of star formation and the process by which galaxies formed. One may in addition track the evolution of the dark energy and discover the net neutrino mass. We are at the dawn of a new era in which hundreds of square degrees of sky can be mapped with arcminute resolution and sensitivities measured in microKelvin. Acquiring these data requires the use of special purpose telescopes such as the Atacama Cosmology Telescope (ACT), located in Chile, and the South Pole Telescope (SPT). These new telescopes are outfitted with a new generation of custom mm-wave kilo-pixel arrays. Additional instruments are in the planning stages.
4 citations
Posted Content•
TL;DR: The Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT) are equipped with a new generation of custom mm-wave kilo-pixel arrays.
Abstract: How did the universe evolve? The fine angular scale (l>1000) temperature and polarization anisotropies in the CMB are a Rosetta stone for understanding the evolution of the universe. Through detailed measurements one may address everything from the physics of the birth of the universe to the history of star formation and the process by which galaxies formed. One may in addition track the evolution of the dark energy and discover the net neutrino mass.
We are at the dawn of a new era in which hundreds of square degrees of sky can be mapped with arcminute resolution and sensitivities measured in microKelvin. Acquiring these data requires the use of special purpose telescopes such as the Atacama Cosmology Telescope (ACT), located in Chile, and the South Pole Telescope (SPT). These new telescopes are outfitted with a new generation of custom mm-wave kilo-pixel arrays. Additional instruments are in the planning stages.
4 citations
01 Oct 2009
TL;DR: In this article, a new parameter A L that scales the lensing potential is introduced, where A L = 0 corresponds to the unlensed model, while AL = 1 is the expected lensed scenario in the standard Λ C D M model.
Abstract: The ACBAR collaboration claimed at the beginning of the last year a detection of a weak gravitational lensing signal at more than 3 standard deviations, based only on the smoothing of the acoustic oscillations in the Cosmic Microwave Background (hereafter CMB) anisotropies power spectrum. In order to reproduce and to study the ACBAR result I introduce a new parameter A L that scales the lensing potential such as: A L = 0 corresponds to the unlensed model while A L = 1 is the expected lensed scenario in the standard Λ C D M model. Here I present the constraints obtained on this new lensing parameter analysing several datasets of CMB temperature and polarization anisotropies.
1 citations